Aubergine flowers but no fruit?

I have flowers on my outdoor Aubergines but no fruit (as far as I can see). There have been bees and wasps flying into the flowers so I assume they are being pollinated.
Is it worth keeping the plants going given that there is no fruit on them?

Mine are the same this year Yana, and I've never had to 'tickle' my aubergines before!   

Mine this year are actually in my little greenhouse.  The best ones I grew were outside in big pots.  2 years ago I planted them in my polytunnel and got a not bad result, but not like the ones that were outside.

I grew these last year and I remember reading from somewhere that they need colossal amounts of water, and the flowers can just drop off if they haven't had enough.  Mine were in buckets in a plastic greenhouse with the door open and when it got really warm I had to water them twice a day.

Mine have had loads of water daily.  I tried them in the greenhouse which is shaded, as they are supposed to be indoor grown, but like I said earlier, the best ones I've grown were in pots outside.